Problem: $\dfrac{5}{2} - \dfrac{6}{8} = {?}$
Explanation: $ = {\dfrac{5 \times 4}{2 \times 4}} - {\dfrac{6 \times 1}{8 \times 1}} $ $ = {\dfrac{20}{8}} - {\dfrac{6}{8}} $ $ = \dfrac{{20} - {6}}{8} $ $ = \dfrac{14}{8}$